P
US9255519B2ExpiredUtilityPatentIndex 93

Fuel management system for variable ethanol octane enhancement of gasoline engines

Assignee: MASSACHUSETTS INST TECHNOLOGYPriority: Nov 18, 2004Filed: Sep 5, 2014Granted: Feb 9, 2016
Est. expiryNov 18, 2024(expired)· nominal 20-yr term from priority
Inventors:COHN DANIEL RHEYWOOD JOHN BBROMBERG LESLIE
F02B 47/00F02D 41/0025F02B 7/00F02M 25/00F02P 5/045F02M 25/14F02B 17/00F02D 19/08F02B 51/00F02B 17/005F02B 47/04F02D 35/027F02D 2200/1002F02D 2041/389F02D 41/3094F02D 19/081Y02T10/148Y02T10/12
93
PatentIndex Score
13
Cited by
88
References
31
Claims

Abstract

Fuel management system for efficient operation of a spark ignition gasoline engine. Injectors inject an anti-knock agent such as ethanol directly into a cylinder of the engine. A fuel management microprocessor system controls injection of the anti-knock agent so as to control knock and minimize that amount of the anti-knock agent that is used in a drive cycle. It is preferred that the anti-knock agent is ethanol. The use of ethanol can be further minimized by injection in a non-uniform manner within a cylinder. The ethanol injection suppresses knock so that higher compression ratio and/or engine downsizing from increased turbocharging or supercharging can be used to increase the efficiency or the engine.

Claims

exact text as granted — not AI-modified
The invention claimed is:  
     
       1. A fuel management system for a turbocharged or supercharged spark ignition engine where the fuel management system controls fueling from a first fueling system that directly injects fuel into at least one cylinder as a liquid and increases knock suppression by vaporization cooling and from a second fueling system that injects fuel into a region outside of the cylinder;
 and where there is a range of torque where both fueling systems are used at the same value of torque; 
 and where the fraction of fuel in the cylinder that is introduced by the first fueling system decreases with decreasing torque and the fuel management system controls the change in the fraction of fuel introduced by the first fueling system using closed loop control that utilizes a sensor that detects knock; 
 and where the fuel management system also employs spark retard so as to reduce the amount of fuel that is introduced into the cylinder by the first fueling system. 
 
     
     
       2. The fuel management system of  claim 1  where the spark retard is employed to as to reduce the amount of fuel that is provided by the first fueling system to zero. 
     
     
       3. The fuel management system of  claim 1  where when the torque is increased the increase in the fraction of fuel that is introduced by the first fueling system is minimized while still preventing knock. 
     
     
       4. The fuel management system of  claim 1  where without employing the spark retard there is a range of torque in which only the second fueling system is used. 
     
     
       5. The fuel management system of  claim 1  where the fuel management system employs the spark retard in response to sensed information and both the sensed information and information about knock are used to control the fuel that is introduced by the first fueling system. 
     
     
       6. The fuel management system of  claim 1  where the maximum torque that the engine provides occurs when both the first and second fueling systems are used at the same value of torque. 
     
     
       7. The fuel management system of  claim 1  where the only the first fueling system is used at the maximum torque that the engine provides. 
     
     
       8. The fuel management system of  claim 1  where only the first fueling system is used when the highest knock resistance is required. 
     
     
       9. The fuel management system of  claim 1  where both the first and second fueling system are used when the highest knock resistance is required. 
     
     
       10. The fuel management system of  claim 1  where as the torque is increased the increase in the fraction of fuel in the cylinder that is provided by the first fueling system is substantially equal to that needed to prevent knock. 
     
     
       11. The fuel management system of  claims 1  or  3  where the fuel management system minimizes the increase in the fraction of fuel in the cylinder that is provided by the first fueling system as torque is increased. 
     
     
       12. The fuel management system of  claim 1  where the second fueling system uses port fuel injection. 
     
     
       13. A fuel management system for a spark ignition engine that controls fueling from a first fueling system that directly injects fuel into at least one cylinder as a liquid and increases knock suppression by vaporization cooling and from a second fueling system that provides fuel to the cylinder using port fuel injection;
 and where the fuel management system uses information from a sensed parameter to control spark retard so as to decrease the amount of fuel that would otherwise be provided by the first fueling system; 
 and where the fuel management system uses input that includes input from the sensed parameter and input from knock sensor. 
 
     
     
       14. The fuel management system of  claim 13  where input from the knock sensor is utilized in a closed loop control system that controls the fraction of fuel that is introduced into the first fueling system. 
     
     
       15. The fuel management system of  claim 13  where both the first and second fueling systems are used at the same value of torque. 
     
     
       16. The fuel management system of  claim 13  where spark retard is employed so as to reduce the use of the first fueling system to zero. 
     
     
       17. The fuel management system of  claim 13  where the engine is turbocharged or supercharged and the level of turbocharging or supercharging is reduced so as to decrease the amount of fuel from the first fueling system. 
     
     
       18. The fuel management system of  claim 13  where closed loop control with a knock detector is used to increase the relative amount of fuel from the first fueling system as torque is increased. 
     
     
       19. A fuel management system for a turbocharged or supercharged spark ignition engine where the fuel management system controls fueling from a first fueling system that directly injects fuel into at least one cylinder as a liquid and increases knock suppression by vaporization cooling and from a second fueling system that introduces fuel into the cylinder by port fuel injection;
 and where during a driving cycle there is a first torque range where both fueling systems are used at the same torque and where the fraction of fuel in the cylinder that is introduced by the first fueling system is increased so as to prevent knock as torque increases; 
 and where the fuel management system matches the fraction of fuel that is provided by first fueling system with the amount needed to prevent knock at a given value of torque; and 
 
       where the fuel management system uses closed loop control that employs a knock detector. 
     
     
       20. The fuel management system of  claim 19  where there is a second torque range where only the second fueling system is used and the highest value of torque in the second torque range is lower than at least one value of torque in the first torque range. 
     
     
       21. The fuel management system of  claim 19  where the fuel management system minimizes the amount of fuel from the first fueling system while still preventing knock. 
     
     
       22. The fuel management system of  claim 19  where the maximum knock resistance required by the engine is in the first torque range. 
     
     
       23. The fuel management system of  claim 19  where for the maximum knock resistance required by the engine only the first fueling system is used. 
     
     
       24. A fuel management system for a spark ignition engine that controls fueling from a first fueling system that introduces fuel into at least one cylinder as a liquid and increases knock resistance by vaporization cooling and from a second fueling system;
 and where the knock resistance of fuel introduced by the first fueling system is greater than the knock resistance of fuel introduced by the second fueling system; 
 and where the fuel management system uses information from a sensed parameter to control spark retard so as to decrease the amount of fuel that would otherwise be provided by the first fueling system; 
 and where the fuel management system uses input that includes input from the sensed parameter and input from knock sensor. 
 
     
     
       25. The fuel management system of  claim 24  where input from the knock sensor is utilized in a closed loop control system that controls the fraction of fuel that is introduced into the first fueling system. 
     
     
       26. The fuel management system of  claim 24  where both the first and second fueling systems are used at the same value of torque. 
     
     
       27. The fuel management system of  claim 24  where spark retard is employed so as to reduce the use of the first fueling system to zero. 
     
     
       28. The fuel management system of  claim 24  where turbocharging or supercharging is used and the level of turbocharging or supercharging is reduced so as to decrease the amount of fuel from the first fueling system. 
     
     
       29. The fuel management system of  claim 24  where closed loop control with a knock detector is used to increase the relative amount of fuel firm the first fueling system as torque is increased. 
     
     
       30. The fuel management system of  claim 24  where the first fueling system uses direct injection. 
     
     
       31. The fuel management system of  claim 24  where the second fueling system uses port fuel injection.

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